Several synthetic fluorocarbon compounds are known to be useful as blood substitutes. Such compounds are described in U.S. Pat. No. 3,911,138 (Clark, 1975), which describes emulsions that contain perfluorinated cyclic hydrocarbons, and U.S. Pat. Nos. 4,110,474 and 4,187,252 (Lagow et al, 1978 and 1980), which describe emulsions that contain perfluorotetramethyl pentane. However, continuing work is being done to create and identify other compounds which are also suitable as blood substitutes, perfusion media, breathable liquids, and for other biological and chemical purposes. Such compounds are likely to have superior qualities regarding one or more relevant characteristics, which include: oxygen affinity and release, solubility or emulsifiability in various media, low toxicity, high shelf life, appropriate stability within the body, low retention within vital organs of the body, and low cost of manufacture.
As used herein, the prefix "perfluoro-" and the term "perfluorinated" indicate that all or essentially all of the replaceable atoms (such as hydrogen) in a compound have been replaced by fluorine atoms. As used herein, the term "hydrocarbon" refers to molecules that contain hydrogen and carbon atoms, regardless of whether they also contain oxygen, fluorine or other atoms.